JPH11325685A - Heating element cooling device - Google Patents

Abstract

[PROBLEMS] To provide a cooling device having excellent performance for cooling heat generated by power supply when inspecting electrical characteristics of a large number of integrated circuits formed on a semiconductor wafer and having high working efficiency. SOLUTION: The cooling device is provided with a cooling block 4 on which a semiconductor wafer 1 is placed in surface contact and which has a supply port and a recovery port of a high thermal conductive fluid 12 (abbreviated as a fluid) on a contact surface. The surface has a collection port 15a at the center and a collection port 1a at a portion corresponding to the outer peripheral edge of the semiconductor wafer 1 on the outer peripheral side.
0a, concentric annular grooves connected to the recovery ports 15a, 10a are provided, and a supply port 7a and an annular groove connected to the supply port 7a are provided between the annular grooves. When cooling, the fluid is supplied from the supply port 7a. Then, the fluid is recovered from the inner and outer peripheral recovery ports 15a and 10a via the respective annular grooves, and at the time of fluid recovery after cooling, gas is supplied from the central recovery port 15a to extrude the fluid in the outer peripheral direction, and the respective annular grooves are formed. It controls so that it may be recovered from the supply port 7a and the recovery port 15a via the interface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a heating element, which cools the heating element and maintains it at a predetermined temperature with high accuracy.
In particular, the present invention relates to a heating element cooling device suitable for cooling a heating element such as a semiconductor wafer that is heated by power supply when inspecting electrical characteristics of an integrated circuit formed on a semiconductor wafer.

[0002]

2. Description of the Related Art Conventionally, as this type of semiconductor wafer cooling apparatus, there is an apparatus described in Japanese Patent Application Laid-Open No. 5-109847. In this conventional example, as shown in FIGS. 12 and 13, a semiconductor wafer 1 as a heating element is placed on a cooling block 4 having a built-in cooling pipe 6 through which a low-temperature cooling fluid supplied from a refrigerator 5 circulates. Then, the semiconductor wafer is vacuum-chucked by a vacuum pump 11 through a vacuum exhaust port 10 a provided in the cooling block 4, and supplied to the center of the cooling block 4 through a flow path 7 provided in the cooling block 4. Helium gas is supplied from a tank 8 as a highly thermally conductive fluid between the contact surface between the semiconductor wafer 1 and the cooling block 4 through the port 7a. The heat generated in the semiconductor wafer 1 is transferred to the high thermal conductive fluid 1
The cooling liquid is transmitted to the cooling block 4 through the cooling pipe 2 and is released to the outside by the cooling liquid flowing in the cooling pipe 6 provided therein.

[0003]

However, in the conventional semiconductor wafer cooling apparatus, since the high thermal conductive fluid is supplied from one location in the center of the semiconductor wafer, the moving distance of the high thermal conductive fluid is long, and the entire semiconductor wafer is moved. When supplying a highly thermally conductive fluid, it takes a long time in proportion to the size of the semiconductor wafer. If the supply amount of the high thermal conductive fluid is increased in order to shorten this time, there is a risk that the pressure will increase and the semiconductor wafer will be lifted. Next, if the area of the opening of the supply port 7a is increased in order to reduce the pressure, the cooling performance of the central portion of the semiconductor wafer will be reduced.

In addition, when a liquid is used as a high thermal conductive fluid in order to improve the cooling performance with an increase in the heat generation amount of the semiconductor wafer, the viscosity of the high thermal conductive fluid increases, and thus the high thermal conductivity accompanying the replacement of the semiconductor wafer increases. In the case of discharging the conductive fluid, it takes a long time just to stop the supply of the high thermal conductive fluid and discharge the fluid from the vacuum exhaust port.

To solve these problems, Japanese Patent Laid-Open Publication No.
In the apparatus described in 101947, FIG.
As shown in FIG. 15, a plurality of supply ports 7a and vacuum exhaust ports 10a are respectively provided on the upper surface of the cooling block 4 to shorten the moving distance of the highly thermally conductive fluid on the upper surface of the cooling block 4. However, from the supply port 7a to the vacuum exhaust port 10a
Alternatively, since the distance to the recovery groove 13 is not equal, the pressure loss (fluid resistance) is different, and there is a possibility that the high heat conductive fluid is not supplied to the entire region formed by the supply port 7a and the recovery groove 13, resulting in cooling performance. There is a problem that the reliability of the device decreases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling device for a heating element which improves the cooling performance and reliability of a semiconductor wafer cooling device, shortens the time for replacing a semiconductor wafer, and improves work efficiency. .

[0007]

According to a first aspect of the present invention, there is provided a cooling device for mounting a heating element and cooling the cooling element via a contact surface with the heating element. A supply port for supplying the high thermal conductive fluid to the contact surface of the body, and a recovery port for recovering the high thermal conductive fluid flowing from the supply port through the minute gap formed by the unevenness of the contact surfaces of the heating element and the cooling element, Fluid supply means for supplying the high thermal conductive fluid to the supply port through a flow path formed in the cooling body, and fluid recovery means for sucking the high thermal conductive fluid from another recovery path through another flow path formed in the cooling body A cooling device for a heating element, comprising: a recovery port, a central recovery port provided at a central portion of a contact surface of the cooling element; and an outer peripheral side provided at a portion of a contact surface of the cooling element corresponding to an outer peripheral portion of the heating element. It consists of a recovery port, and this recovery port is centered around the recovery port. The supply port comprises an intermediate supply port provided between the central recovery port and an annular groove connected to the outer peripheral side recovery port, and the intermediate supply port is connected to the central recovery port. Is connected to an annular groove provided around the center, and each of the outer circumferential and intermediate annular grooves is formed in a shape similar to the outer shape of the heating element.

In the cooling device for a heating element, it is preferable that the distance from the center recovery port to the annular groove connected to the intermediate supply port is equal to the distance between the intermediate and outer peripheral annular grooves.

In the cooling device for the heating element,
When cooling the heating element, the high thermal conductive fluid is supplied from the intermediate supply port through the annular groove connected to the intermediate supply port, and when the cooling of the heating element is stopped and the high thermal conductive fluid is collected, the cooling element is cooled. By supplying gas from the central recovery port, the high heat conductive fluid is pushed out from the center of the cooling body in the outer peripheral direction, and is recovered from the intermediate supply port through the annular groove connected to the intermediate supply port, and is connected to the outer peripheral side recovery port. It is controlled so that it is collected from the outer peripheral collection port through the groove. At the time of recovery, it is preferable to supply gas intermittently.
If the gas is continuously supplied, the heating element rises from the cooling body, and it becomes difficult to discharge the high heat conductive fluid. Expedites drainage of conductive fluid.

A second aspect of the present invention, like the first aspect, further comprises a cooling body that contacts and cools the heating element, and has a supply port for a highly thermally conductive fluid on the contact surface of the cooling element. A cooling device for a heating element comprising a recovery port, a fluid supply means, and a fluid recovery means, wherein an even number of multiple annular grooves are provided around the center of the contact surface of the cooling body, and the recovery port is provided at the center of the cooling body. And the supply port consists of a port connected to the even-numbered annular groove from the inside, while the supply port consists of a port connected to the odd-numbered annular groove, and the outermost annular groove is provided on the outer periphery of the heating element. It is formed at a corresponding position and in a shape similar to the outer shape of the heating element. The heating element cooled by the cooling device is a semiconductor wafer.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the present invention will be described below with reference to FIGS. 1 and 5 are longitudinal sectional views of a heating device cooling device according to Embodiment 1 of the present invention. 2, 3, 4, 6, and 7 are surface views of the contact surface of the cooling block 4 of the cooling device for the heating element according to the first embodiment. In FIGS. 1 and 2, a semiconductor wafer 1 is an object to be evaluated for electric characteristics, and a silicon wafer is usually used frequently. When evaluating a large number of integrated circuits formed on the upper surface of the semiconductor wafer 1 one by one, power is supplied to a power supply circuit and a signal circuit in the integrated circuit each time, and the semiconductor wafer 1 becomes a heating element. When evaluating the electrical characteristics of each integrated circuit, the semiconductor wafer 1 needs to be cooled because power is supplied at a constant temperature in order to remove the influence of temperature change on the characteristics.

Above the semiconductor wafer 1, the semiconductor wafer 1
A contact probe pin 2 for supplying power to the integrated circuit and extracting a test signal and a probe card 3 for holding the probe pin 2 are provided. The semiconductor wafer 1 as a heating element is mounted on the upper surface of a cooling block 4 as a cooling element. In FIG. 1, the contact state between the cooling block 4 and the semiconductor wafer 1 is schematically illustrated as being in contact with each other via an equivalent gap. In both cases, the surface roughness and the warpage are on the order of several μm. Therefore, when they actually come into contact with each other, the microscopic irregularities on the surface collide with each other, and a minute gap exists in the concave. Since such a microscopic situation is difficult to illustrate, the simulated equivalent gap is shown as described above to indicate the existence of a minute gap in the concave portion.

The cooling device for a heating element according to the present embodiment comprises a cooling block 4 on which the semiconductor wafer 1 is mounted, and a cooling pipe 6 partially formed in the cooling block 4.
Chiller 5 that supplies refrigerant to cooling block 4 through
And a tank 16 for supplying water as a highly thermally conductive fluid 12 between a contact surface between the semiconductor wafer 1 and the cooling block 4 from a supply port 7 a through a forward channel 7 provided in the cooling block 4.
And the pump 17 and the flow path 10 returning the high thermal conductive fluid 12 from the recovery ports 10 a and 15 a provided in the cooling block 4.
And a collection device 11 that collects the collected data through the storage device 15.

More specifically, the cooling block 4 is cooled by the refrigerant supplied from the refrigerator 5 through the built-in cooling pipe 6, and the refrigerant is returned to the refrigerator 5 again to form a circulation channel. . The cooling block 4
A circumferential supply groove 14 having a similar shape to the outer periphery of the semiconductor wafer 1 is provided at a position substantially corresponding to the middle from the center to the outer periphery of the semiconductor wafer 1.
And the supply port 7a serving as an intermediate supply port is connected. The supply port 7a is supplied with a highly thermally conductive fluid 12 from a tank 16 via a pump 17 for controlling the flow rate to be constant. Further, on the upper surface of the cooling block 4, at a position corresponding to the outer peripheral edge portion of the semiconductor wafer 1, a circular collecting groove 13 connected to the collecting port 10 a as an outer peripheral side collecting port, and at a central portion of the semiconductor wafer 1. A collection port 15a as a central collection port is provided at a corresponding position. The collecting groove 13 and the collecting port 15a are preferably provided at equal distances in the radial direction from the supply groove 14 located therebetween. The high thermal conductive fluid 12 flowing out of the supply port 7a spreads annularly from the supply groove 14 toward the center and the outer periphery of the upper surface of the cooling block 4 as shown in FIG. The spread high thermal conductive fluid layer 20 is formed, and is recovered by the recovery device 11 through the recovery ports 10a and 15a.

Next, a heat conduction path will be described. Heat generated by power supply to the power supply circuit and the signal circuit formed on the semiconductor wafer 1 is transmitted to the cooling block 4 via the highly heat-conductive fluid layer 20 interposed between the power supply circuit and the signal block, and provided therein. The cooling liquid flowing through the cooling pipe 6 is released to the outside. Here, the layer referred to as the high thermal conductive fluid layer has a small unevenness due to the surface roughness and warpage of about several μm on the contact surface between the semiconductor wafer 1 and the cooling block 4. It includes a portion that makes solid contact between them and a minute gap where the high thermal conductive fluid 12 exists.

In the present embodiment, the supply groove 14 is provided substantially at the center from the center to the outer periphery of the semiconductor wafer 1, so that the distance from the supply groove 14 to the collection groove 13 and the distance from the supply groove 14 to the collection port 15a. , The high heat conductive fluid 12 can be supplied to the minute gap between the semiconductor wafer 1 and the cooling block 4 in a short time, and the working efficiency is improved. Further, since the supply opening area can be made larger by providing the supply groove 14 connected to the supply port 7a without concentrating the opening area of the supply port 7a at one place, the cooling performance is not reduced and the high thermal conductive fluid 12 Even if the supply amount is increased, the pressure does not increase and the danger of lifting the semiconductor wafer 1 is reduced, and the reliability of the cooling performance is improved. Further, by providing the distance between the supply groove 14 and the outer recovery groove 13 and the distance between the supply groove 14 and the inner recovery port 15a to be equal, the moving distance of the high thermal conductive fluid 12 becomes equal, and the pressure increases. Since the loss (fluid resistance) is constant, the high heat conductive fluid 12 is supplied to the entire region formed by the supply groove 14 and the recovery groove 13 and the supply groove 14 and the recovery port 15a, and thus the reliability of the cooling performance of the apparatus is reliable. The performance is improved.

Next, in order to replace the semiconductor wafer 1 after the inspection is completed, all the high thermal conductive fluid 12 interposed in the gap between the semiconductor wafer 1 and the cooling block 4 is discharged. As shown in FIG. 5, the pump 1 is first discharged from the high thermal conductive fluid 12.
By stopping the supply of 7, the supply of the high thermal conductive fluid 12 is stopped, the valve 18 is switched, the valve 21 is opened, and the high thermal conductive fluid 12 is recovered from the intermediate supply port 7a simultaneously with the recovery port 10a on the outer peripheral side. Next, the valve 19 is switched, the valve 9 is opened, the gas in the tank 8 is supplied from the central recovery port 15a, and the high heat conductive fluid 12 is supplied from the center of the cooling block 4 to the outer peripheral direction as shown in FIG. Extrude. When the high heat conductive fluid 12 is lost in the region from the center of the cooling block 4 to the middle supply groove 14, the valve 21
Is closed, and the high thermal conductive fluid 12 is
As shown in FIG. 7, all of the highly thermally conductive fluid 12 interposed in the gap between the semiconductor wafer 1 and the cooling block 4 is discharged.

In the present embodiment, when recovering the high thermal conductive fluid 12, a gas is supplied from the center of the cooling block 4 and the high thermal conductive fluid 12 is pushed out from the center of the cooling block 4 toward the outer periphery. By controlling so as to recover the high thermal conductive fluid 12 from the supply groove 14 and the recovery groove 13 connected to the radially middle supply port 7a and the outer recovery port 10a, respectively, Even when the liquid is used, the highly thermally conductive fluid 12 can be discharged in a short time, and the working efficiency is improved. Further, a thin heating element such as the semiconductor wafer 1 is provided with a highly heat conductive fluid 12.
If the gas is continuously supplied from the central portion to extrude the gas, the central portion rises, and a large gap is generated between the semiconductor wafer 1 and the cooling block 4. At this time, the high thermal conductive fluid 12
When a highly viscous liquid is used, the liquid adheres to the semiconductor wafer 1 side and the cooling block 4 side in the form of water droplets due to surface tension, so that it is difficult to extrude the liquid in a short time.
Therefore, when a large gap is formed between the semiconductor wafer 1 and the cooling block 4, the supply of gas is stopped once, the gap is reduced, and the gas is supplied again to push the liquid toward the recovery groove. . Repeating this series of actions,
That is, by supplying the gas intermittently, it becomes possible to recover the high thermal conductive fluid 12 in a shorter time, and the working efficiency is further improved. If hot air or dry air is used as the gas to be supplied, it is possible to recover the highly thermally conductive fluid in a shorter time.

Next, a second embodiment of the present invention will be described with reference to FIGS.
1 will be described. FIG. 8 is a longitudinal sectional view of a heating device cooling device according to Embodiment 2 of the present invention. 9, 10, and 11
FIG. 7 is a surface view of a contact surface of a cooling block 4 constituting a cooling device for a heating element according to a second embodiment. 8 and 9, the difference from the first embodiment is that the number of supply grooves 14 and the number of recovery grooves 13 are increased. That is, on the upper surface of the block 4, a collecting port 15a is provided at the center, and a plurality of supply grooves and collecting grooves are sequentially provided around the collecting port 15a alternately at equal intervals to form a multiple circle. 8 and FIG. 1 when cooling the heating element in the same manner as in the first embodiment.
As shown in FIG.
As described in the first embodiment, an effect is obtained that the highly thermally conductive fluid 12 can be supplied in a short time with a reduced pressure loss without lifting the semiconductor wafer. Also, at the time of recovering the high thermal conductive fluid 12, FIG.
By supplying the gas in the tank 8 from the central recovery port 15a and pushing out the high heat conductive fluid 12 from the center of the cooling block 4 toward the outer periphery as shown in FIG. The collection time of the high thermal conductive fluid 12 is reduced, and the working efficiency is improved. Embodiment 2 of the present invention
Is particularly effective when the size of the semiconductor wafer 1 is further increased.

Further, the present invention provides a wafer probing test apparatus and a semiconductor CVD apparatus without departing from the scope of the present invention.
Applicable to equipment, etching equipment, etc.

[0021]

As described above, according to the present invention, the following effects can be obtained. According to the first aspect, the annular groove connected to the supply port is provided at a position corresponding to substantially the middle from the center to the outer periphery of the heating element on the upper surface of the cooling body, so that the annular groove is connected to the recovery port outside the annular groove. The distance to the groove or the center recovery port is shortened, and a high heat conductive fluid can be supplied to the minute gap between the heating element and the cooling element in a short time, thereby improving the working efficiency. In addition, since the opening area of the supply port can be substantially increased without concentrating at one place by providing the annular groove, the pressure is high even if the supply amount of the high heat conductive fluid is increased without lowering the cooling performance. In addition, since the lifting of the heating element can be suppressed, the reliability of the cooling performance of the device is improved. In addition, the distance between the annular groove for supply and the annular groove for recovery, and the interval between the groove for supply and the central recovery port are respectively equalized, so that the moving distance of the highly thermally conductive fluid is equal, and the pressure loss (fluid resistance) is reduced. ) Is constant, the highly thermally conductive fluid can be smoothly supplied to the entire area where the heating element and the cooling element are in contact with each other, and the reliability of the cooling performance of the device is improved.

Further, when recovering the high thermal conductive fluid from the gap between the heating element and the cooling body, a gas is supplied from the central recovery port of the cooling body, and the high thermal conductive fluid is pushed out from the central portion toward the outer periphery, and each of them is annular. By controlling to collect from the intermediate supply port and the outer peripheral side recovery port through the groove, it is possible to discharge the highly thermally conductive fluid in a short time even if a highly viscous liquid is used as the highly thermally conductive fluid. Work efficiency is improved. In addition, intermittent supply of gas from the central recovery port of the cooling body is effective when cooling a thin heating element such as a semiconductor wafer. That is, if the gas continues to be supplied from the central part to push out the high thermal conductive fluid, the central part may be lifted. At this time, the high thermal conductive fluid adheres to the heating element and the cooling element in the form of water drops due to surface tension. Since it is difficult to extrude the gas with gas in a short time, it is preferable to temporarily extinguish the gas supply, to reduce the gap, and to supply the gas again to extrude the highly thermally conductive fluid. By repeating this series of operations, that is, by supplying gas intermittently, it becomes possible to recover the highly thermally conductive fluid in a shorter time, thereby further improving the working efficiency and reducing the inspection cost.

According to a second aspect of the present invention, a recovery port for the highly heat conductive fluid is provided at the center of the contact surface of the cooling body, and a plurality of supply ports and recovery ports are alternately provided as the distance from the center increases, so that the supply port is separated from the center. Since the port and the recovery port are sequentially connected to the multiple annular grooves having the center of the contact surface, it is useful for cooling a heating element having a large area.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a cooling device for a heating element according to Embodiment 1 of the present invention.

FIG. 2 is a view of a contact surface of the cooling block shown in FIG.

FIG. 3 is a diagram showing the spread of a highly thermally conductive fluid on a contact surface of the cooling block shown in FIG. 1;

FIG. 4 is a diagram showing further wetting and spreading of the highly thermally conductive fluid at the contact surface of the cooling block shown in FIG. 1;

FIG. 5 is a diagram illustrating recovery of a highly thermally conductive fluid according to the first embodiment of the present invention.

FIG. 6 is a diagram for explaining the outflow of a highly thermally conductive fluid from a cooling block contact surface during recovery.

FIG. 7 is a diagram for explaining the outflow of a highly thermally conductive fluid from a cooling block contact surface during recovery.

FIG. 8 is a longitudinal sectional view of a cooling device for a heating element according to Embodiment 2 of the present invention.

9 is a view of the contact surface of the cooling block shown in FIG.

FIG. 10 is a view for explaining wet spreading of a highly thermally conductive fluid at the time of cooling on a contact surface of the cooling block shown in FIG. 8;

FIG. 11 is a view for explaining the outflow of the highly thermally conductive fluid at the time of recovery from the contact surface of the cooling block shown in FIG. 8;

FIG. 12 is a longitudinal sectional view of a conventional semiconductor wafer cooling device.

FIG. 13 is a view of the contact surface of the cooling block of FIG.

FIG. 14 is a view of a contact surface of a cooling block in a conventional semiconductor wafer cooling device.

FIG. 15 is a view of another contact surface of a cooling block in a conventional semiconductor wafer cooling device.

[Description of Signs] 1 Semiconductor wafer of heating element 4 Cooling block 5 Refrigerator 6 Coolant circulating pipe 7a Supply port 8 Gas tank 10a Recovery port 11 Fluid recovery device 12 High thermal conductive fluid 13 Recovery groove 14 Supply groove 15a Recovery port 16 High thermal conductive fluid tank 17 Pump 20 High thermal conductive fluid layer

Continuation of front page (72) Inventor Koji Ozawa 2326 Imai, Ome-shi, Tokyo Inside the Device Development Center, Hitachi, Ltd.

Claims (6)

[Claims] 1. A cooling element for mounting a heating element and cooling the heating element through a contact surface with the heating element, a supply port for supplying a high thermal conductive fluid to the contact surface of the cooling element, and A recovery port for recovering a high thermal conductive fluid flowing through a minute gap formed by the unevenness of the contact surface of each of the heating element and the cooling element; and a high thermal conductivity through a flow path formed in the cooling body at the supply port. A cooling device for a heating element, comprising: a fluid supply unit that supplies a fluid; and a fluid recovery unit that sucks a highly thermally conductive fluid from the recovery port through another flow path formed in the cooling body. A central recovery port provided at the center of the contact surface of the cooling body and an outer circumference side recovery port provided at a portion of the contact surface of the cooling body corresponding to the outer circumference of the heating element; and In the annular groove formed around the center recovery port The supply port comprises an intermediate supply port provided between the center recovery port and an annular groove connected to the outer peripheral side recovery port, and the intermediate supply port is provided around the center recovery port. A cooling device for a heating element, wherein each of the annular grooves is formed in a shape similar to the outer shape of the heating element by being connected to a groove. 2. The cooling device for a heating element according to claim 1, wherein the distance from the central recovery port to the annular groove connected to the intermediate supply port is equal to the distance between the annular grooves. 3. When the heating element is cooled, a high thermal conductive fluid is supplied from the intermediate supply port through an annular groove connected to the intermediate supply port, while cooling the heating element is stopped. When recovering, the gas is supplied from the center recovery port of the cooling body, the high heat conductive fluid is extruded from the center of the cooling body in the outer peripheral direction, and from the intermediate supply port through the annular groove connected to the intermediate supply port. The cooling device for a heating element according to claim 1 or 2, wherein the heat is recovered from the outer peripheral side recovery port through an annular groove connected to the outer peripheral side recovery port. 4. The cooling device for a heating element according to claim 3, wherein the gas is supplied intermittently. 5. A cooling unit for mounting a heating element and cooling the cooling element via a contact surface with the heating element, a supply port for supplying a high thermal conductive fluid to the contact surface of the cooling element, and A recovery port for recovering a high thermal conductive fluid flowing through a minute gap formed by the unevenness of the contact surface of each of the heating element and the cooling element; and a high thermal conductivity through a flow path formed in the cooling body at the supply port. A cooling device for a heating element, comprising: a fluid supply unit that supplies a fluid; and a fluid recovery unit that sucks a highly thermally conductive fluid from the recovery port through another flow path formed in the cooling body. An even number of annular grooves are provided around the center of the contact surface, and the recovery port comprises a port provided in the center of the cooling body and a port connected to the even numbered annular groove from the inside, and the supply port is an odd number. From the mouth connected to the annular groove of Ri, the heating element of the cooling device, characterized in that the annular groove of the outermost position corresponding to the outer peripheral portion of the heating element, and is formed in the outer shape similar to the shape of the heating element. 6. The cooling device according to claim 1, wherein the heating element is a semiconductor wafer.